Liquid crystal device including color filter formed on reflecting film having openings and electronic device using the same

ABSTRACT

The present invention provides a transflective liquid crystal device in which color display can be made uniform over the display surface in both the reflective display mode and the transmissive display mode. The liquid crystal device can include a pair of substrates which sandwich liquid crystal, a light reflecting film formed on the substrate, and a color filter formed on the light reflecting film. The color filter can include a partitioning member, which divides the surface of the substrate into a plurality of sections, and subpixels which are individually formed in the sections. The light reflecting film is provided with openings formed at regions corresponding to the thickest parts of the subpixels, openings formed at regions corresponding to central parts of the section, openings which extend in longitudinal direction of the rectangular sections, or openings formed in the shape corresponding to the thickness distribution of the subpixels.

This is a Divisional Application of U.S. patent application Ser. No.10/043,240 filed on Jan. 14, 2002, now U.S. Pat. No. 6,690,448, thecontents of which are incorporated herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates to transflective liquid crystal devices bywhich a reflective display that uses light reflected after passingthrough a liquid crystal layer and a transmissive display that useslight transmitted through the liquid crystal layer can be manufactured,and in which a color filter can be disposed on a light path so thatcolor display can be realized.

2. Description of Related Art

Recently, liquid crystal devices have come into widespread use inelectronic devices, such as mobile phones, portable computers, etc. Insuch liquid crystal devices, reflective liquid crystal devices, in whicha light reflecting film is provided on an inside or outside surface of asubstrate disposed at the side opposite to the observer's side of aliquid crystal layer, are known in the art. In reflective liquid crystaldevices, light incident from the observer's side is reflected at thelight reflecting film, and is used as a light source for display.

In addition, transmissive liquid crystal devices, in which anilluminating device, that is, a so-called backlight, is disposed at theside opposite to the observer's side of a liquid crystal layer and isused as a light source for display, are also know in the art. Inaddition, transflective liquid crystal devices, in which openings areformed in a light reflecting film, and in which reflective display isrealized using regions excluding the openings in the light reflectingfilm and transmissive display is realized using the light passing theopenings in the light reflecting film, are also known in the art.

On the other hand, recently, color display is often realized in liquidcrystal devices by disposing a color filter having R (red), G(green),and B(blue) or C(cyan), M(magenta), and Y(yellow) subpixels, in adisplay area of the liquid crystal devices.

SUMMARY OF THE INVENTION

According to a known technique of color transflective displays, in whichopenings are formed in a light reflecting film and a color filter isused, uniform color display over the display area cannot be realized.The inventors have performed various experiments to discover the reasonfor this, and found that color display cannot be made uniform if therelationship between the openings in the light reflecting film and theR, G, and B or C, M, and Y subpixels regarding position and shape arenot adequately coordinated.

In view of the above-described finding, an object of the presentinvention is to provide a transflective liquid crystal device in whichcolor display can be made uniform over the display surface in both thereflective display mode and the transmissive display mode.

In order to attain the above-described object, according to a firstaspect of the present invention, a liquid crystal device can include apair of substrates which sandwich liquid crystal, a light reflectingfilm formed on at least one of the substrates, and a color filter formedon the light reflecting film. The color filter can include apartitioning member, which divides the surface of the substrate into aplurality of sections, and subpixels, which are individually formed inthe sections, and openings are formed in the light reflecting film atregions corresponding to thickest parts of the subpixels.

The partitioning member may be formed by, for example, applying anink-repellent resin at a uniform thickness by a known deposition method,for example, spin coating, and forming a predetermined pattern by aknown patterning method, for example, photolithography. In addition, theabove-described subpixels are formed by, for example, an inkjet method,that is, by ejecting, in the form of drops, a subpixel material fromnozzles of an inkjet head toward the sections devided by thepartitioning member.

In the liquid crystal device according to the first aspect of thepresent invention, as shown in FIG. 5, openings 18 are formed in a lightreflecting film 9 at regions corresponding to thickest parts ofsubpixels 16. Thus, in the reflective display mode, light that passesthrough the subpixels 16 to and from the light reflecting film 9 atparts excluding the thickest parts of the subpixels 16, as shown by thearrow X0, is used for color display. In addition, in the transmissivedisplay mode, light that passes through the subpixels 16 at thickestparts thereof, as shown by the arrow X1, is used for color display.

Accordingly, light that is transmitted through the subpixels 16 once atthe thickest parts thereof is used in the transmissive display mode, andlight that is transmitted through the subpixels 16 twice at relativelythin parts thereof is used in the reflective display mode. Accordingly,the optical thickness in the reflective display mode and that in thetransmissive display mode can be made close or approximately the same,so that color display can be made uniform between the reflective displaymode and the transmissive display mode.

According to a second aspect of the present invention, a liquid crystaldevice can include a pair of substrates which sandwich liquid crystal, alight reflecting film formed on at least one of the substrates, and acolor filter formed on the light reflecting film. The color filter caninclude a partitioning member, which divides the surface of thesubstrate into a plurality of sections, and subpixels, which areindividually formed in the sections, and openings are formed in thelight reflecting film at regions corresponding to central parts of thesections.

The partitioning member may be formed by, for example, applying anink-repellent resin at a uniform thickness by a known deposition method,for example, spin coating, and forming a predetermined pattern by aknown patterning method, for example, photolithography. In addition, theabove-described subpixels are formed by, for example, the inkjet method,that is, by ejecting, in the form of drops, a subpixel material fromnozzles of an inkjet head toward the sections.

As shown in FIG. 5(a) and FIG. 5(c), in the case in which the subpixels16 are formed by the inkjet method, the subpixels 16 tend to swellupward at central regions of the sections divided by a partitioningmember 14. Accordingly, when the openings 18 are formed in the lightreflecting film 9 at regions corresponding to the central parts of thesections divided by the partitioning member 14, the optical thickness inthe reflective display mode and that in the transmissive display modecan be made close or approximately the same. Thus, color display can bemade uniform between the reflective display mode and the transmissivedisplay mode.

According to a third aspect of the present invention, a liquid crystaldevice can include a pair of substrates which sandwich liquid crystal, alight reflecting film formed on at least one of the substrates, and acolor filter formed on the light reflecting film. The color filter caninclude a partitioning member, which divides the surface of thesubstrate into a plurality of rectangular sections, and subpixels, whichare individually formed in the rectangular section, and openings areformed in the light reflecting film in such a manner that the openingsextend in the longitudinal direction of the rectangular sections.

The partitioning member may be formed by, for example, applying anink-repellent resin at a uniform thickness by a known deposition method,for example, spin coating, and forming a predetermined pattern by aknown patterning method, for example, photolithography. In addition, theabove-described subpixels are formed by, for example, the inkjet method,that is, by ejecting, in the form of drops, a subpixel material fromnozzles of an inkjet head toward the sections.

Generally, in order to realize color display, especially full-colordisplay, a unit including R, G, and B subpixels functions as a pixel,and a full-color image is displayed by controlling the color illuminatedin each pixel. The R, G, and B subpixels are often formed in arectangular shape. In such a case, as shown in FIG. 5(b), thepartitioning member 14 forms a plurality of rectangular sections, andthe subpixels 16 are individually formed in the sections.

In the case in which the subpixels 16 are formed in the rectangularshape as seen from top, the openings 18 are preferably formed in arectangular shape that extends in the longitudinal direction of thesubpixels 16. Accordingly, in the transmissive display mode, sufficientamount of light that is uniform in the longitudinal direction of thesubpixels 16 can be supplied to the subpixels 16, so that uniform colordisplay can be realized.

According to a fourth aspect of the present invention, a liquid crystaldevice can include a pair of substrates which sandwich liquid crystal, alight reflecting film formed on at least one of the substrates,-and acolor filter formed on the light reflecting film. The color filter caninclude a partitioning member, which divides the surface of thesubstrate into a plurality of sections, and subpixels, which areindividually formed in the sections, and openings are formed in thelight reflecting film in such a manner that the openings have a shapecorresponding to the thickness distribution of the subpixels.

The partitioning member may be formed by, for example, applying anink-repellent resin at a uniform thickness by a known deposition method,for example, spin coating, and forming a predetermined pattern by aknown patterning method, for example, photolithography. In addition, theabove-described subpixels are formed by, for example, the inkjet method,that is, by ejecting, in the form of drops, a subpixel material fromnozzles of an inkjet head toward the sections.

In the case in which the subpixels are formed by supplying ink, that is,a subpixel material to the sections divided by the partitioning member,the thickness of the subpixels may not be uniform. For example, as shownin FIG. 5(a) and FIG. 5(c), the subpixels 16 may be formed in a convexshape, in other words, shaped like a dome. When the thickness of thesubpixels 16 is not uniform, the openings 18 are preferably formed onlyat regions corresponding to the parts of the subpixels 16 where thethickness thereof is larger than a reference value TO. Accordingly, thecolor display can be made more uniform between the reflective displaymode and the transmissive display mode.

In the case in which the openings are formed in the light reflectingfilm in the shape corresponding to the thickness distribution of thesubpixels, the shape of the openings is effectively determined utilizinglight interference fringes. More specifically, as shown in FIG. 8(a),natural light R0 is radiated on the subpixel 16, and light reflectedform the light reflecting film 9 is photographed by a camera 30. Then,when the photographed image is displayed, interference fringes F, whichare schematically shown in FIG. 8(b), are obtained in accordance withthe thickness distribution of the subpixel 16. The interference fringesF can be assumed as contour lines of the subpixel 16. Accordingly, whenthe openings 18 are formed in the light reflecting film in the shape ofone of the interference fringes F which are selected, the openingshaving a shape that accurately corresponds to the thickness distributionof the subpixels can be obtained.

In the liquid crystal device according to one of the above-describedfirst to fourth aspects of the present invention, the openingspreferably have a planner shape such that the corners thereof are cutoff. For example, the corners of the openings may be formed as beveledcorners M1 shown in FIG. 6(b), rounded corners M2 shown in FIG. 7(b).

The subpixels formed in the sections divided by the partitioning membertend to have a convex shape such that the central parts thereof arethick and the peripheral parts thereof are thin. In addition, thesurfaces of the subpixels are curved in three-dimensional space alongthe diagonal lines of the sections. In such a case, when the corners ofthe openings in the light reflecting film are formed in an angular shapeof, for example, 90°, uniformity of color may be degraded at the cornersof the openings. In contrast, when the openings have a shape such thatthe corners thereof are cut off as described above, uniform colordistribution can be obtained.

In addition, in the liquid crystal device according to one of theabove-described first to fourth aspects of the present invention, theplanner shape of opening may have a rectangular shape, an oval shape, oran elliptical shape. The elliptical shape is a shape in which thecorners of a rectangle are rounded in a certain way, and the oval shapeis a shape excluding the elliptical shape that can also be obtained byrounding the corners of a rectangle.

When the openings are formed in one of the above-described shapes, colordisplay can be made more uniform compared with the case in which theopenings are formed in a square shape.

In addition, in the liquid crystal device according to one of theabove-described first to fourth aspects of the present invention, thearea of a single opening is 5% to 30%, and preferably about 20% of thearea of a single section. When the aperture ratio is in theabove-described range, satisfactory visibility can be achieved in boththe reflective display mode and the transmissive display mode. When theaperture ratio is larger than the above-described range, display canbecome unclear since a sufficient amount of reflected light cannot beobtained by an illuminating device. When the aperture ratio is smallerthan the above-described range, the display can become unclear sincesufficient illumination cannot be obtained.

According to another aspect of the present invention, a manufacturingmethod for a liquid crystal device, in which liquid crystal issandwiched between a pair of substrates, at least one of which includesa color filter, can include forming a light reflecting film on one ofthe substrates, forming a partitioning member which divides the surfaceof the substrate into a plurality of sections, and forming subpixels inthe sections divided by the partitioning member. The step of forming thesubpixels can further include ejecting, in the form of drops, a materialfor forming the subpixels from nozzles toward the sections and the stepof forming the light reflecting film includes the step of formingopenings in the light reflecting film at regions corresponding to thesections.

In the manufacturing method for the liquid crystal device according tothe present invention, each subpixel can be formed by the inkjet method.Thus, the relationships between the openings formed in the lightreflecting film and the subpixels can be individually adjusted, so thatthe colors displayed by the subpixels can be individually and preciselyadjusted. Accordingly, uniform color display over the display area canbe realized.

In the manufacturing method for the liquid crystal device according tothe present invention, the openings can be formed in the lightreflecting film at regions corresponding to thickest parts of thesubpixels in the step of forming the light reflecting film. Accordingly,light that is transmitted through the subpixels once at the thickestparts thereof is used in the transmissive display mode, and light thatis transmitted through the subpixels twice at relatively thin partsthereof is used in the reflective display mode. Accordingly, the opticalthickness in the reflective display mode and that in the transmissivedisplay mode can be made closer or approximately the same, so that colordisplay can be made uniform between the reflective display mode and thetransmissive display mode.

In addition, in the manufacturing method for the liquid crystal deviceaccording to the present invention, the openings are preferably formedin the light reflecting film at regions corresponding to central partsof the sections in the step of forming the light reflecting film. Asshown in FIG. 5(a) and FIG. 5(c), in the case in which the subpixels 16are formed by the inkjet method, the subpixels 16 tend to swell upwardat central regions of the sections divided by the partitioning member14. Accordingly, when the openings 18 are formed in the light reflectingfilm 9 at regions corresponding to the central parts of the sectionsdivided by the partitioning member 14, the optical thickness in thereflective display mode and that in the transmissive display mode can bemade close or approximately the same. Thus, color display can be madeuniform between the reflective display mode and the transmissive displaymode.

In addition, in the manufacturing method for the liquid crystal deviceaccording to the present invention, the surface of the substrate may bedivided into a plurality of rectangular sections in the step of formingthe partitioning member. In such a case, the openings are preferablyformed in the light reflecting film in such a manner that the openingsextend in the longitudinal direction of the rectangular sections in thestep of forming the light reflecting film. Accordingly, in thetransmissive display mode, a sufficient amount of light that is uniformin the longitudinal direction of the subpixels can be supplied to thesubpixels, so that uniform color display can be realized.

In addition, in the manufacturing method for the liquid crystal deviceaccording to the present invention, the openings are preferably formedin the light reflecting film in such a manner that the openings have ashape corresponding to the thickness distribution of the subpixels inthe step of forming the light reflecting film. In color display, densityof color is significantly effected by the thickness of the subpixels.Thus, uniformity of color density can be degraded when the openings areformed irrespective of the thickness distribution of the subpixels. Incontrast, uniform color display can be obtained when the shape of theopenings is determined based on thickness distribution of the subpixels.

In addition, in the manufacturing method for the liquid crystal deviceaccording to the present invention, the openings having a shape suchthat the corners thereof are cut off are preferably formed in the lightreflecting film in the step of forming the light reflecting film. Thesubpixels formed in sections divided by the partitioning member tend tohave a convex shape such that the central parts thereof are thick andthe peripheral parts thereof are thin. In addition, the surfaces of thesubpixels are curved in three-dimensional space along the diagonal linesof the sections. In such a case, when the corners of the openings areformed in an angular shape of, for example, 90°, uniformity of color maybe degraded at the corners of the openings. In contrast, when theopenings have a shape such that the corners thereof are cut off asdescribed above, uniform color distribution can be obtained.

In addition, in the manufacturing method for the liquid crystal deviceaccording to the present invention, the planner shape of opening havinga rectangular shape, an oval shape, or an elliptical shape arepreferably formed in the light reflecting film in the step of formingthe light reflecting film. The elliptical shape is a specific shape inwhich the corners of a rectangle are rounded in a certain way, and theoval shape is a shape excluding the elliptical shape that can also beobtained by rounding the corners of a rectangle. When the openings areformed in one of the above-described shapes, color display can be mademore uniform compared with the case in which the openings are formed ina square shape.

In addition, in the manufacturing method for the liquid crystal deviceaccording to the present invention, the openings are preferably formedin the light reflecting film in such a manner that the area of a singleopening is 5% to 30%, and preferably about 20% of the area of a singlesection in the step of forming the light reflecting film. When theaperture ratio is in the above-described range, satisfactory visibilitycan be ensured in both the reflective display mode and the transmissivedisplay mode. When the aperture ratio is larger than the above-describedrange, display becomes unclear since a sufficient amount of reflectedlight cannot be obtained. When the aperture ratio is smaller than theabove-described range, the display becomes unclear since sufficientillumination cannot be obtained by an illuminating device.

In the liquid crystal device according to the present invention, thesubpixels may be formed in a convex shape such that the central partsthereof swell upward.

In the manufacturing method for the liquid crystal device according tothe present invention, the subpixels may be formed in a convex shapesuch that the central parts thereof swell upward.

According to another aspect of the present invention, a liquid crystaldevice comprises a pair of substrates which sandwich liquid crystal; alight reflecting film formed on at least one of the substrates; and acolor filter formed on the light reflecting film. The color filter caninclude a partitioning member, which divides the surface of thesubstrate into a plurality of sections, and subpixels, which areindividually formed in the sections. The subpixels are formed in aconcave shape such that the central parts thereof are hollow, andopenings are formed in the light reflecting film at regionscorresponding to thickest parts of the subpixels.

According to another aspect of the present invention, a liquid crystaldevice can include a pair of substrates which sandwich liquid crystal, alight reflecting film formed on at least one of the substrates, and acolor filter formed on the light reflecting film. The color filterincludes a partitioning member, which divides the surface of thesubstrate into a plurality of sections, and subpixels, which areindividually formed in the sections. The subpixels are formed in aconcave shape such that the central parts thereof are hollow, andopenings are formed in the light reflecting film at regionscorresponding to part of peripheral parts of the sections in such amanner that the peripheral parts of the sections are partly or entirelycovered by the openings.

According to another aspect of the present invention, a liquid crystaldevice can include a pair of substrates which sandwich liquid crystal, alight reflecting film formed on at least one of the substrates, and acolor filter formed on the light reflecting film. The color filterincludes a partitioning member, which divides the surface of thesubstrate into a plurality of rectangular sections, and subpixels, whichare individually formed in the rectangular sections. The subpixels areformed in a concave shape such that the central parts thereof arehollow, and, and openings are formed in the light reflecting film insuch a manner that the openings extend in the longitudinal direction orthe lateral direction of the rectangular sections at regionscorresponding to peripheral parts of the rectangular sections.

According to another aspect of the present invention, a liquid crystaldevice can include a pair of substrates which sandwich liquid crystal, alight reflecting film formed on at least one of the substrates, and acolor filter formed on the light reflecting film. The color filterincludes a partitioning member, which divides the surface of thesubstrate into a plurality of sections, and subpixels, which areindividually formed in the sections. The subpixels are formed in aconcave shape such that the central parts thereof are hollow, andopenings are formed in the light reflecting film in such a manner thatthe openings have a shape corresponding to the thickness distribution ofthe subpixels.

In the manufacturing method for the liquid crystal according to thepresent invention, the subpixels may be formed in a concave shape suchthat the central parts thereof are hollow in the step of forming thesubpixels, and the openings may be formed in the light reflecting filmat regions corresponding to thickest parts of the subpixels in the stepof forming the light reflecting film.

In addition, in the manufacturing method for the liquid crystal deviceaccording to the present invention, the subpixels may be formed in aconcave shape such that the central parts thereof are hollow in the stepof forming the subpixels, and the openings may be formed in the lightreflecting film at regions corresponding to peripheral parts of thesections in such a manner that the peripheral parts of the sections arepartly or entirely covered by the opening in the step of forming thelight reflecting film.

In addition, in the manufacturing method for the liquid crystal deviceaccording to the present invention, the subpixels may be formed in aconcave shape such that the central parts thereof are hollow in the stepof forming the subpixels, and the openings may be formed in the lightreflecting film at regions corresponding to peripheral parts of therectangular sections in such a manner that the openings extend in thelongitudinal direction or the lateral direction of the rectangularsections in the step of forming the light reflecting film.

In addition, in the manufacturing method of the liquid crystal deviceaccording to the present invention, the subpixels may be formed in aconcave shape such that the central parts thereof are hollow in the stepof forming the subpixels, and the openings may be formed in the lightreflecting film in such a manner that the openings have a shapecorresponding to the thickness distribution of the subpixels in the stepof forming the light reflecting film.

According to another aspect of the present invention, an electronicdevice comprises a liquid crystal device which is constructed asdescribed above and a housing which contains the liquid crystal device.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described with reference to theaccompanying drawing, wherein like numbers reference like elements, andwherein:

FIG. 1 is an exploded perspective view showing an embodiment of a liquidcrystal device according to the present invention;

FIG. 2 is a sectional view of the liquid crystal device shown in FIG. 1taken along line I—I;

FIG. 3 is an enlarged view of a part shown by the arrow D in FIG. 1;

FIG. 4 is a schematic representation showing patterns in which subpixelsare arranged in a color filter;

FIG. 5 is a schematic representation showing an example of aconstruction of a single pixel in a color filter, where (a) is asectional view of subpixels taken along the lateral direction thereof,(b) is a plan view of the subpixels, and (c) is a sectional view of oneof the subpixels taken along the longitudinal direction thereof;

FIG. 6 is a schematic representation showing another example of aconstruction of a single pixel in a color filter, where (a) is asectional view of subpixels taken along the lateral direction thereof,(b) is a plan view of the subpixels, and (c) is a sectional view of oneof the subpixels taken along the longitudinal direction thereof;

FIG. 7 is a schematic representation showing another example of aconstruction of a single pixel in a color filter, where (a) is asectional view of subpixels taken along the lateral direction thereof,(b) is a plan view of the subpixels, and (c) is a sectional view of oneof the subpixels cut along the longitudinal direction thereof;

FIG. 8 is a schematic representation showing an example of a manner inwhich the color filter is formed, where (a) shows an example of ameasurement system for obtaining interference fringes, and (b) is theinterference fringes obtained by the measurement system;

FIG. 9 is a flowchart showing an embodiment of a liquid crystal devicemanufacturing method according to the present invention;

FIG. 10 is a schematic representation showing mother substrates formedin one of the processes shown in FIG. 9;

FIG. 11 is a flowchart showing a process of forming a color filter,which is one of the processes shown in FIG. 9;

FIG. 12 is a perspective view showing an inkjet device used in one ofthe processes shown in FIG. 11;

FIG. 13 is an enlarged perspective view of a major part of the inkjetdevice shown in FIG. 12;

FIG. 14 is a schematic representation showing an example of an inkjethead used in the inkjet device shown in FIG. 12 and head chips includedin the inkjet head;

FIG. 15 is a perspective view showing a modification of the head chipincluded in the inkjet head;

FIG. 16 is a schematic representation showing an internal structure ofthe head chip included in the inkjet head, where (a) is a partiallybroken perspective view of the head chip and (b) is a sectional view of(a) taken along line J—J;

FIG. 17 is a block diagram showing an electrical control system used inthe inkjet device shown in FIG. 12;

FIG. 18 is a flowchart showing a control process implemented by thecontrol system shown in FIG. 17;

FIG. 19 is a schematic representation showing a process of forming acolor filter, which is a main process of the liquid crystal devicemanufacturing method according to the embodiment;

FIG. 20 is a schematic representation showing a process of forming acolor filter, which is a main process of a liquid crystal devicemanufacturing method according to another embodiment;

FIG. 21 is a schematic representation showing a process of forming acolor filter, which is a main process of a liquid crystal devicemanufacturing method according to another embodiment;

FIG. 22 is a schematic representation showing another example of aconstruction of a single pixel in a color filter, where (a) is asectional view of subpixels taken along the lateral direction thereof,(b) is a plan view of the subpixels, and (c) is a sectional view of oneof the subpixels taken along the longitudinal direction thereof;

FIG. 23 is a schematic representation showing another example of aconstruction of a single pixel in a color filter, where (a) is asectional view of subpixels taken along the lateral direction thereof,(b) is a plan view of the subpixels, and (c) is a sectional view of oneof the subpixels taken along the longitudinal direction thereof;

FIG. 24 is a schematic representation showing another example of aconstruction of a single pixel in a color filter, where (a) is asectional view of subpixels taken along the lateral direction thereof,(b) is a plan view of the subpixels, and (c) is a sectional view of oneof the subpixels taken along the longitudinal direction thereof;

FIG. 25 is a schematic representation showing another example of aconstruction of a single pixel in a color filter, where (a) is asectional view of subpixels taken along the lateral direction thereof,(b) is a plan view of the subpixels, and (c) is a sectional view of oneof the subpixels taken along the longitudinal direction thereof;

FIG. 26 is a perspective view showing an embodiment of an electronicdevice according to the present invention;

FIG. 27 is a perspective view showing another embodiment of anelectronic device according to the present invention; and

FIG. 28 is a front view showing another embodiment of an electronicdevice according to the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention will be explained below in conjunction withembodiments. FIG. 1 is an exploded view showing an embodiment of aliquid crystal device according to the present invention, and FIG. 2 isa sectional view of the liquid crystal device shown in FIG. 1 takenalong line I—I. A liquid crystal device 1 of the present embodiment isan active matrix liquid crystal device using Thin Film Diodes (TFDs),which are two-terminal switching elements, as active elements. Inaddition, the liquid crystal device 1 is also a transflective liquidcrystal device having both functions of reflective display andtransmissive display, and a Chip On Glass (COG) type liquid crystaldevice in which an IC chip is directly mounted on a substrate.

With reference to FIG. 1, a liquid crystal panel 2 can be formed bylaminating a first substrate 3 a and a second substrate 3 b with anannular sealing member 4. Then, liquid crystal L is injected into a gap,that is, a so-called cell gap, formed between the first and secondsubstrates 3 a and 3 b. Then, liquid crystal driving ICs 6 a and 6 b aremounted on the first and second substrates 3 a and 3 b, respectively,and an illuminating device 7 is disposed at the side opposite to theobserver's side, that is, outside the first substrate 3 a in the presentembodiment, as a backlight. The liquid crystal device 1 is thusconstructed.

The liquid crystal driving ICs 6 a and 6 b are mounted using, forexample, Anisotropic Conductive Films (ACFs). In addition, liquidcrystal L is injected into the cell gap through an opening 4 a formed inthe sealing member 4 at a suitable position for passing the liquidcrystal L therethrough. After the liquid crystal L is injected, theopening 4 a is sealed by a resin, etc.

As shown in FIG. 2, the first substrate 3 a can include a first baseplate 8 a formed of glass, plastic, etc., having a rectangular shapewhen viewed along the arrow B. In addition, a light reflecting film 9, acolor filter 11, first electrodes 12 a, and an alignment film 13 a areformed on the inside surface of the first base plate 8 a (the uppersurface in FIG. 2), in that order. In addition, a polarizing plate 19 ais laminated on the outside surface of the first base plate 8 a.

As shown in FIG. 5(a), the color filter 11 can include a bank 14 whichis formed on the light reflecting film 9 in a matrix pattern as seenform the arrow C and which serves as a partitioning member, a pluralityof subpixels 16 which are individually disposed in the plurality ofsections formed by the bank 14, and protecting films 17 which areindividually formed on the subpixels 16. In the present embodiment, thesubpixels 16 and the protecting films 17 are both formed by an inkjetmethod, which will be described below.

Although FIG. 5 shows enlarged views of only some of the subpixels 16(substantially three), the color filter 11 is constructed such that alarge number of subpixels 16 are arranged in the longitudinal andlateral directions to form a matrix pattern when viewed along the arrowC. Each of the subpixels 16 functions as a dot for displaying anindividual color, and a group consisting of three subpixels (a redsubpixel 16R, a green subpixel 16G, and a blue subpixel 16B) form asingle pixel.

As shown in FIG. 5(a) and FIG. 5(c), which are sectional views of thesubpixels 16, each of the subpixels 16 is formed in a convex shape inwhich the highest part is at the center P, in other words, shaped like adome. Conceivably, this shape is naturally formed when the subpixels 16are formed by the inkjet method, that is, when a subpixel material isejected toward the sections in the form of drops.

The subpixels 16 can be divided into red subpixels 16R, green subpixels16G, and blue subpixels 16B, and are arranged in, for example, a stripedpattern (FIG. 4(a)), a mosaic pattern (FIG. 4(b)), a deltoid pattern(FIG. 4(c)), etc. In the striped pattern, subpixels 16 of the same colorare arranged in a line. In the mosaic pattern, three successivesubpixels 16 correspond to R, G, and B both in the longitudinal andlateral directions. In the deltoid pattern, the subpixels 16 arearranged in a staggered manner such that three adjacent pixelscorrespond to R, G, and B.

With reference to FIG. 5(a), in the present embodiment, the bank 14 isformed by applying a nontransparent resin by a suitable coating method,for example, spin coating, and forming a pattern by a suitablepatterning method, for example, photolithography. Since the bank 14 isformed of a nontransparent resin, the bank 14 also functions as a blackmask which prevents light from leaking from the color filter 11. Ofcourse, an additional black mask may also be disposed under the bank 14.

The protecting films 17 are normally formed of a transparent resinmaterial, and can function, for example, as follows. Firstly, thesurface of the color filter substrate can be flattened by forming theprotecting films 17, so that electrodes can be prevented from being cutin the process of forming the electrodes on the surface of the colorfilter substrate. Secondly, the resistances of the electrodes formed onthe protecting films 17 can be reduced, so that the contrast ratiobetween the pixels can be increased. Thirdly, the protecting films 17can serve as protectors; more specifically, the protecting films 17prevent the pixels formed in the color filter substrate from beingdamaged in processes performed after the protecting films 17 are formed.Fourthly, when the color filter substrate is installed in the liquidcrystal device and liquid crystal is injected into the cell gap, theprotecting films 17 prevent impurities from being diffused into theliquid crystal.

With reference to FIG. 1, the light reflecting film 9 can be formed byapplying a light reflecting metal material such as Al, Ag, etc., andalloys thereof, at a uniform thickness by a suitable deposition method,for example, sputtering, and forming a pattern by a suitable patterningmethod, for example, photolithography. In the patterning process,openings 18 are formed in the light reflecting film 9 at regions forforming the subpixels, that is, positions corresponding to theindividual sections formed by the bank 14.

As shown in FIGS. 5(a) to 5(c), in the present embodiment, the openings18 are individually formed at central regions P of the sections formedby the bank 14, that is, regions corresponding to the thickest parts ofthe subpixels 16. In addition, as shown in FIG. 5(b), in the presentembodiment, each of the openings 18 is formed in a rectangular shapethat extends in the longitudinal direction of each subpixel 16.

With reference to FIG. 2, the first electrodes 12 a are formed in astriped pattern when viewed along the arrow B. In FIGS. 1 and 2, a smallnumber of first electrodes 12 a with broad gaps therebetween are shownin order to facilitate the understanding of the pattern of the firstelectrodes 12 a, however, in practice, a large number of firstelectrodes 12 a are formed with extremely narrow gaps therebetween. Thefirst electrodes 12 a are formed by applying, for example, Indium TinOxide (ITO) at a uniform thickness by a suitable deposition method, forexample, sputtering, and forming a predetermined pattern such as thestriped pattern, etc., by a suitable patterning method, for example,photolithography.

In FIG. 1, the first electrodes 12 a are formed so as to extend beyondthe sealing member 4, so that the first electrodes 12 a can beelectrically connected to output bumps, that is, output terminals, ofthe Liquid crystal driving IC 6 a. The Liquid crystal driving IC 6 asupplies the first electrodes 12 a with scanning signals or datasignals.

The alignment film 13 a is formed by, for example, applying a polyimidesolution and baking it. The alignment film 13 a is subjected to analignment process, for example, a rubbing process, which determines thealignment of liquid crystal molecules in the liquid crystal L at theregion close to the surface of the first substrate 3 a.

In FIG. 1, the second substrate 3 b includes a second base plate 8 bformed of glass, plastic, etc., having a rectangular shape, and aplurality of second electrodes 12 b are formed on the inside surface ofthe second base plate 8 b (the lower surface in FIG. 1) in a matrixpattern. Although the second electrodes 12 b are schematically shown inFIG. 1 at a large size in order to facilitate the understanding thereof,it should be understood that in practice, a large number of extremelysmall second electrodes 12 b can be formed.

FIG. 3 is an enlarged view of a part of the second substrate 3 b shownby the arrow D in FIG. 1. With reference to FIG. 3, an electrical line21, TFD units 22 which extend from the electrical line 21 and whichfunction as switching elements, and second electrodes 12 b which areconnected to the electrical line 21 via the TFD units 22 are formed onthe inside surface of the second base plate 8 b. As shown in FIG. 1, thesecond electrodes 12 b are arranged in a dot-matrix pattern as describedabove.

Processes for forming the above-described components will be describedbelow. First, a first layer 21 a of the electrical line 21 and firstmetal films 22 a of the TFD units 22 are formed by applying, forexample, Tantalum (Ta) at a uniform thickness by sputtering and forminga pattern of the first layer 21 a and the first metal films 22 a. Then,a second layer 21 b is formed on the first layer 21 a of the electricalline 21 and insulating films 22 b are formed on the first metal films 22a of the TFD units 22 by an anodizing process. Then, a third layer 21 cis formed on the second layer 21 b of the electrical line 21 and secondmetal films 22 c are formed on the insulating films 22 b of the TFDunits 22 by applying, for example, chromium (Cr) at a uniform thicknessby sputtering and forming a pattern of the third layer 21 c and thesecond metal films 22 c. There are two kinds of second metal films 22 c: one kind of second metal film 22 c extends from the electrical line 21and overlaps the insulating films 22 b and the other kind of secondmetal film 22 c connects the insulating films 22 b and the secondelectrodes 12 b.

Accordingly, each of the TFD units 22 includes a first TFD element 23 aat the side close to the electrical line 21 and a second TFD element 23b at the side close to the second electrodes 12 b. The first TFD element23 a has a Metal-Insulator-Metal (MIM) structure in which the secondmetal film 22 c, the insulating film 22 b, and the first metal film 22 aare laminated in that order from the electrical line 21. In addition,the second TFD element 23 b has a Metal-Insulator-Metal (MIM) structurein which the first metal film 22 c, the insulating film 22 b, and thesecond metal film 22 c are laminated in that order from the electricalline 21.

The above-described structure of the TFD units 22, in which two TFDelements are serially connected in an electrically reversed manner, iscalled a “back-to-back” structure, and is used to obtain stableswitching characteristics. In the case in which the required stabilityof the switching characteristics is not very high, a TFD unitconstructed of a single TFD element may also be used in place of the TFDelement having the back-to-back structure.

The second electrodes 12 b, which are individually connected to thesecond metal films 22 c of the second TFD elements 23 b, can be formedby applying, for example, ITO, at a uniform thickness by a suitabledeposition method, for example, sputtering, and forming a pattern by asuitable patterning method, for example, photolithography. Withreference to FIG. 1, the first electrodes 12 a can be arranged on thefirst substrate 3 a, which opposes the second substrate 3 a, in adirection such that the first electrodes 12 a cross the electrical line21 shown in FIG. 3, for example, in the direction perpendicular to theelectrical line 21.

With reference to FIG. 2, an alignment film 13 b is formed on the secondelectrodes 12 b. Although the second electrodes 12 b having a relativelylarge size are schematically shown in FIG. 2 in order to facilitate theunderstanding thereof, in practice, a large number of extremely smallsecond electrodes 12 b are formed. The alignment film 13 b is formed by,for example, applying a polyimide solution and baking it. The alignmentfilm 13 b is subjected to an alignment process, for example, a rubbingprocess, which determines the alignment of the liquid crystal moleculesin the liquid crystal L at the region close to the surface of the secondsubstrate 3 b.

A polarizing plate 19 b can be laminated on the outside surface of thesecond base plate 8 b. The polarizing plate 19 b is aligned such thatthe polarization axis thereof is at a predetermined angle relative tothe polarization axis of the polarizing plate 19 a formed on the firstsubstrate 3 a.

In FIG. 1, the electrical lines 21 are formed on the second substrate 3b so as to extend beyond the sealing member 4, so that the electricallines 21 can be electrically connected to output bumps, that is, outputterminals, of the Liquid crystal driving IC 6 b. One of the scanningsignals and data signals is supplied to the first electrodes 12 a by theliquid crystal driving IC 6 a, and the other one of the scanning signalsand data signals is supplied to the TFD units 22 by the liquid crystaldriving IC 6 b via the electrical lines 21.

With reference to FIG. 1, the illuminating device 7, which is disposedat the rear side of the first substrate 3 a, that is, the side oppositeto the observer's side, includes a transparent plate 24 and a pluralityof (for example, three) LEDs 26, which serve as light sources. Thetransparent plate 24 has approximately the same area as the firstsubstrate 3 a, and the LEDs 26 are disposed such that the LEDs 26 opposea light entrance 24 a, which is one of the side surfaces of thetransparent plate 24. The transparent plate 24 is formed of acrylicresin, polycarbonate resin, glass, etc. Light incident from the lightentrance 24 a is transmitted through the light entrance 24 a, isuniformly emitted via a light exit surface 24 b, which faces the liquidcrystal panel 2, and is supplied to the liquid crystal panel 2.

With reference to FIG. 2, the first substrate 3 a and the secondsubstrate 3 b are laminated by the sealing member 4. The cell gap formedbetween the first and the second substrates 3 a and 3 b is maintained byspacers 27, which are sprayed over one of the first and secondsubstrates 3 a and 3 b, and the liquid crystal L is injected into thecell gap. Twisted Nematic (TN) liquid crystal, for example, is used asthe liquid crystal L.

The liquid crystal device 1 of the present embodiment is constructed asdescribed above. When the liquid crystal device 1 serves as a reflectiveliquid crystal device, external light incident from the outside of thefirst substrate 3 b of an observer in FIG. 2, such as sunlight, roomlight, etc., is transmitted through the liquid crystal L, reflected atthe light reflecting film 9, and supplied to the liquid crystal L.

When the liquid crystal device I serves as a transmissive liquid crystaldevice, light is emitted from the LEDs 26, which are included in theilluminating device 7, is incident on the transparent plate 24 via thelight entrance 24 a, and is uniformly emitted via the light exit surface24 b. Then, the light emitted from the transparent plate 24 istransmitted through the openings 18 formed in the light reflecting film9, and is supplied to the liquid crystal L.

In both cases, that is, in the reflective display and the transmissivedisplay, voltages are applied between the first electrodes 12 a whichsandwich the liquid crystal L and the second electrodes 12 b, whichoppose each other, in accordance with switching operations of the TFDunits 22. Thus, the alignment of the liquid crystal molecules iscontrolled. Light supplied to the liquid crystal L is modulated inaccordance with the above-described alignment control, and is dividedinto polarized light that passes through the polarizing plate 19 b andpolarized light that cannot pass through the polarizing plate 19 b.Accordingly, an image is displayed at the observer's side. At this time,a desired color of R, G, or B can be displayed by allowing light to passthrough the subpixel corresponding to that color.

In the present embodiment, as shown in FIGS. 5(a) to (c), the openings18 are formed in the light reflecting film 9 at regions corresponding tothe thickest parts of the subpixels 16. Thus, in the reflective displaymode, light that passes through the subpixels 16 to and from the lightreflecting film 9 at parts excluding the thickest parts of the subpixels16, as shown by the arrow X0, is used for color display. In addition, inthe transmissive display mode, light that passes through the subpixels16 at the thickest parts thereof, as shown by the arrow X1, is used forcolor display.

Accordingly, light that is transmitted through the subpixels 16 once atthe thickest parts thereof is used in the transmissive display mode, andlight that is transmitted through the subpixels 16 twice at relativelythin parts thereof is used in the reflective display mode. Accordingly,the optical thickness in the reflective display mode and that in thetransmissive display mode can be made close or approximately the same,so that color display can be made uniform between the reflective displaymode and the transmissive display mode.

As shown in FIG. 5(a) and FIG. 5(c), in the case in which the subpixels16 are formed by the inkjet method (which will be described in greaterdetail below), the subpixels 16 tend to swell upward at the centralregions of the sections formed by the bank 14. Accordingly, when theopenings 18 are formed in the light reflecting film 9 at regionscorresponding to the central parts of the sections divided by the bank14, the optical thickness in the reflective display mode and that in thetransmissive display mode can be made close or approximately the same.Thus, uniform color can be made uniform between the reflective displaymode and the transmissive display mode.

In addition, in the present embodiment, a plurality of rectangularsections are formed by the bank 14, as shown in FIGS. 5(a) to (c), andthe subpixels 16 are individually formed in the rectangular sections. Inaddition, the openings 18 formed in the light reflecting film 9 have arectangular shape that extends in the longitudinal direction of therectangular sections. Accordingly, in the transmissive display mode,sufficient amount of light that is uniform in the longitudinal directionof the subpixels 16 can be supplied to the subpixels 16, so that uniformcolor display can be realized.

FIG. 6 shows a modification of the openings 18 formed in the lightreflecting film 9. The openings 18 shown in FIG. 6 are the same as theopenings 18 shown in FIG. 5 according to the above-described embodimentexcept that four corners of the openings 18 are beveled. In order toform the openings 18 having beveled corners M1, a photomask that has apattern including corners corresponding to the above-described beveledcorners M1 is used in the process of forming a pattern on the lightreflecting film 9 by a suitable patterning method, for example,photolithography.

Since the openings 18 having the beveled corners M1 are formed, lightcan be supplied in accordance with the thickness distribution of thesubpixels 16, which is curved along the diagonal line of each sectionformed by the bank 14. Accordingly, uniform color display can berealized.

FIG. 7 shows another modification of the openings 18 formed in the lightreflecting film 9. The openings 18 shown in FIG. 7 are the same as theopenings 18 shown in FIG. 5 according to the above-described embodimentexcept that the four corners of the openings 18 are rounded. Similarlyto the modification shown in FIG. 6, in order to form the openings 18having rounded corners M2, a photomask that has a pattern includingcorners corresponding to the above-described rounded corners M2 is usedin the process of forming a pattern on the light reflecting film 9 by asuitable patterning method, for example, photolithography.

Similarly to the modification shown in FIG. 6, since the openings 18having the rounded corners M2 are formed, light can be supplied inaccordance with the thickness distribution of the subpixels 16, which iscurved along the diagonal line of each section formed by the bank 14.Accordingly, uniform color display can be realized.

The planar shape of the openings 18, which are in the light reflectingfilm 9 such that the openings 18 individually correspond to thesubpixels 16, may also have shapes other than the rectangular shape(FIG. 5(b)), the rectangular shape with beveled corners M1 (FIG. 6(b)),and the rectangular shape with rounded corners M2 (FIG. 7(b)). Forexample, the planar shape of the openings 18 may be an oval shape, whichcan be obtained by changing the dimension of the rounded corners M2shown in FIG. 7(b), an elliptical shape, etc.

FIG. 8 is a diagram showing another method for determining the shape ofthe openings 18 shown in FIG. 5. This method will be described below.

In the case in which the subpixels 16 are formed by supplying ink or asubpixel material to the sections formed by the bank 14 by the inkjetmethod, the thickness of the subpixels 16 may not be uniform. Forexample, as shown in FIG. 5(a) and FIG. 5(c), the subpixels 16 may beformed in a convex shape, in other words, shaped like a dome. When thethickness of the subpixels 16 is not uniform, the openings 18 arepreferably formed in the light reflecting film at regions correspondingto the parts of the subpixels 16 where the thickness thereof is largerthan a reference value T0. Accordingly, the color display can be mademore uniform between the reflective display mode and the transmissivedisplay mode.

In the case in which the openings 18 are formed in the light reflectingfilm 9 in the shape corresponding to the thickness distribution of thesubpixels 16, the shape of the openings 18 is effectively determinedutilizing light interference fringes. More specifically, as shown inFIG. 8(a), natural light R0 is radiated on the subpixel 16, and lightreflected form the light reflecting film 9 is captured by a camera 30.Then, when the captured image is displayed, interference fringes F,which are schematically shown in FIG. 8(b), are obtained in accordancewith the thickness distribution of the subpixel 16. The interferencefringes F can be regarded as contour lines of the subpixel 16.Accordingly, when the openings are formed in the light reflecting filmin the shape of one of the interference fringes F, the openings having ashape that accurately corresponds to the thickness distribution of thesubpixels can be obtained.

The aperture ratio of the openings 18 is set in the range of 5% to 30%,and is preferably set to 20%. The aperture ratio is the ratio of thearea of a single opening 18 to the area of a single section formed bythe bank 14, that is, the area of a single subpixel 16.

When the aperture ratio is in the above-described range, satisfactoryvisibility can be ensured in both the reflective display mode and thetransmissive display mode. When the aperture ratio is larger than theabove-described range, display becomes unclear since a sufficient amountof reflected light cannot be obtained. When the aperture ratio issmaller than the above-described range, the display becomes unclearsince sufficient illumination cannot be obtained by an illuminatingdevice.

FIG. 9 shows an embodiment of a manufacturing method for the liquidcrystal device shown in FIG. 1. In this manufacturing method, P1 to P7are processes for forming the first substrate 3 a, and P11 to P14 areprocesses for forming the second substrate 3 b. Normally, the processesfor forming the first substrate 3 a and the processes for forming thesecond substrate 3 b are individually performed. In the presentembodiment, the first substrate 3 a and the second substrate 3 b havingthe size shown in FIG. 1 are not directly formed. As shown in FIGS.10(a) and 10(b), first, a mother substrate 33 a including a plurality offirst substrates 3 a and a mother substrate 33 b including a pluralityof second substrates 3 b are constructed. Then, the first and the secondsubstrates 3 a and 3 b are obtained by breaking the mother substrates 33a and 33 b, respectively.

With reference to FIG. 9, the processes for forming the first substrate3 a will be described below. First, a first mother base plate 3 8 a oflarge area (see FIG. 10(a)) formed of a transparent glass, a transparentplastic, etc., is prepared, and a plurality of light reflecting films 9for a plurality of liquid crystal panels 2 are formed on the mother baseplate 38 a by photolithography, etc. (P1). Then, the color filters 11are individually formed on the light reflecting films 9 by the inkjetmethod, which will be described below, etc. (P2), and then the firstelectrodes 12 a are formed by photolithography, etc. (P3).

Then, the alignment films 13 a are formed on the first electrodes 12 aby painting, printing, etc. (P4), and then the alignment films 13 a aresubjected to an alignment process, for example, a rubbing process, whichdetermines the initial alignment of the liquid crystal (P5). Next, thesealing members 4 are formed in a shape such that the sealing member 4can individually surround regions corresponding to the liquid crystalpanels 2 by screen printing, etc. (P6), and then spherical spacers 27are spread over the alignment films 13 a (P7). Accordingly, the mothersubstrate 33 a of large area (see FIG. 10(a)) including a plurality ofpanel areas on first substrates 3 a of the liquid crystal panels 2 isformed.

The processes for forming the second substrate 3 b (P11 to P14 in FIG.9) are performed separately from the above-described processes forforming the first substrate 3 a. First, a second mother base plate 38 bof large area (see FIG. 10(b)) formed of a transparent glass, atransparent plastic, etc., is prepared. Then, the electrical lines 21and the switching elements 22 for a plurality of the liquid crystalpanels 2 are formed on the surface of the second mother base plate 38 b(P11), and then the second electrodes 12 b are formed with ITO, etc., byphotolithography, etc. (P12).

Next, the alignment films 13 b (see FIG. 2) are formed by painting,printing, etc. (P13), and then the alignment films 13 b are subjected toan alignment process, for example, a rubbing process, which determinesthe initial alignment of the liquid crystal (P14). Accordingly, themother substrate 33 b of large area including a plurality of panel areason second substrates 3 b of the liquid crystal panels 2 is formed.

After the first mother substrate 33 a of large area and the secondmother substrate 33 b are formed as described above, the mothersubstrates 33 a and 33 b are aligned, that is, the positions andorientations thereof are adjusted. Then, the mother substrates 33 a and33 b are laminated with the sealing member 4 therebetween (P21).Accordingly, a panel unit including a plurality of empty liquid crystalpanels, that is, in which liquid crystal is not yet injected, is formed.

Next, the panel unit including the empty liquid crystal panels is cutinto long rectangular panel pieces in such a manner that the opening 4 a(see FIG. 1) formed in the sealing member 4 for injecting the liquidcrystal is exposed in each of the liquid crystal panels (P22). Then, theliquid crystal L is injected into each of the liquid crystal panelsthrough the opening 4 a for injecting liquid crystal, and then theopening 4 a is sealed by a resin, etc. (P23).

Generally, in the liquid crystal injection process, a container isfilled with liquid crystal and the container filled with liquid crystaland the long rectangular panel pieces including the empty liquid crystalpanels are first put into a chamber, etc. Then, the chamber, etc., isevacuated, and the panel pieces are dipped into the liquid crystal.Then, the chamber is vented to the atmosphere. Since the interiorregions of the empty liquid crystal panels are a vacuum at this time,the liquid crystal, which is pressurized at atmospheric pressure, isdrawn into the liquid crystal panels through the opening for injectingliquid crystal. Since the liquid crystal adheres to the exteriorsurfaces of the panel pieces in the liquid crystal injection process,the panel pieces are cleaned at P24 after the liquid crystal injectionprocess.

Then, after the liquid crystal injection process and the cleaningprocess, the long rectangular panel pieces are subjected to a scribingprocess, that is, a cutting process, so that a plurality of liquidcrystal panels 2 are obtained (P25). Then, as shown in FIG. 1, theLiquid crystal driving ICs 6 a and 6 b are mounted on each of the liquidcrystal panels 2, and the illuminating device 7 is attached to each ofthe liquid crystal panels 2 as a backlight (P26). In addition, thepolarizing plate 19 a is formed on the outside surface of the firstsubstrate 3 a and the polarizing plate 19 b is formed on the outsidesurface of the second substrate 3 b (P27). The liquid crystal device 1is thus completed.

In the processes for forming the first substrate 3 a shown in FIG. 9,the color filter forming process (P2) will be described below in greaterdetail.

FIG. 11 schematically shows processes for forming the color filter 11.First, as viewed along the arrow B, the bank 14 is formed of anontransparent resin material in a matrix pattern on the surface of themother base plate 38 a formed of glass, plastic, etc., on which thelight reflecting film 9 is formed (P31). The subpixels 16 areindividually formed in cells 28 formed by the bank 14 in the matrixpattern.

The size of each cell 28 formed by the bank 14 is, for example, 30μm×100 μm when viewed along the arrow B. The bank 14 is preferablyformed by applying an ink-repellent resin at a uniform thickness by asuitable deposition method, for example, spin coating, and forming apredetermined matrix pattern by a suitable patterning method, forexample, photolithography.

Then, at P32, red, green and blue subpixels 16 are formed in thesections formed by the bank 14 by the inkjet method. More specifically,an inkjet head 52 scans over the mother base plate 38 a, and a subpixelmaterial M6 is ejected from nozzles 57, which are formed in the inkjethead 52, in the form of ink drops at a timing corresponding to one ofthe patterns shown in FIG. 4 and adhered on the mother base plate 38 a.Then, the subpixel material M6 is cured by baking it or by applyingultraviolet rays, thus completing the subpixels 16. The above-describedprocesses are performed for each of the red, green, and blue subpixels16R, 16G, and 16B, so that a desired subpixel pattern can be obtained.

Then, at P33, the protecting films 17 are individually formed on thesubpixels 16 in the sections formed by the bank 14 by the inkjet method.More specifically, similarly to the processes for forming the subpixels16, the inkjet head 52 scans over the mother base plate 38 a, and aprotecting film material M7 is ejected from the nozzles 57 which areformed in the inkjet head 52 toward the subpixel elements in the form ofink drops at a timing corresponding to one of the patterns shown in FIG.4 and adhered on the subpixels 16 on the mother base plate 38 a. Then,the protecting film material M7 is cured by, for example, baking it for30 to 60 minutes at 200° C., thus completing the protecting films 17.

In the inkjet process for forming the subpixels 16 (P32), the inkjethead 52 may scan three times for individually forming the R, G, and Bsubpixels 16. Alternatively, the inkjet head 52 may be provided withthree kinds of nozzles for the three colors (R, G, and B), so that theR, G, and B subpixels 16 can be formed by a single scan.

In addition, in the protecting film forming process (P33), ink drops ofa predetermined volume may be provided to all the sections formed by thebank 14 by a single scan of the inkjet head 52. However, in the case inwhich the subpixels 16 formed in the section have different thicknessesin accordance with the colors thereof, the volume of the ink dropsejected from the nozzles 57 is adjusted in accordance with the colors ofthe subpixels 16.

The inkjet head 52 for the subpixel forming process (P32) and the inkjethead 52 for the protecting film forming process (P33) may be used insequence in a single inkjet apparatus. Alternatively, the inkjet head 52for the subpixel forming process (P32) and the inkjet head 52 for theprotecting film forming process (P33) may be installed in differentinkjet apparatuses, which are operated separately. In addition, a singleinkjet head and a single inkjet apparatus may be used in both thesubpixel forming process (P32) and the protecting layer forming process(P33) by changing the ink supplied to the inkjet head 52 between thesubpixel material and the protecting film material.

In addition, the method for scanning the inkjet head 52 over the motherbase plate 38 a in the subpixel forming process (P32) and the protectingfilm forming process (P33) is not limited, and various methods can beconsidered. For example, the nozzles 57 may be arranged in a line havingthe same length as one side of the mother base plate 38 a, and thesubpixel material M6 and the protecting film material M7 may be suppliedover the entire area of the mother base plate 38 a by a single scan.Alternatively, the nozzles 57 may be arranged in a line that is shorterthan one side of the mother base plate 38 a, and the inkjet head 52 maybe repeatedly moved in a main scanning direction and also in asub-scanning direction for displacing a main sanning positions until inkis supplied over the entire area of the mother base plate 38 a.

FIG. 12 shows an example of an inkjet apparatus used in the subpixelforming process (P32) and the protecting film forming process (P33). Aninkjet apparatus 46 is used for ejecting the subpixel material or theprotecting film material onto the mother base plate 38 a (see FIG.10(a)) at predetermined positions in the substrate section 3 a.

With reference to FIG. 12, the inkjet apparatus 46 can include a headunit 56 having the inkjet head 52, a head position controller 47 whichcontrols the position of the inkjet head 52, a base plate positioncontroller 48 which controls the position of the mother base plate 38 a,a main scanning driver 49 which moves the inkjet head 52 relative to themother base plate 38 a in a main scanning direction, a sub-scanningdriver 51 which moves the inkjet head 52 relative to the mother baseplate 38 a in a sub-scanning direction, a base plate supplying device 53which transfers the mother base plate 38 a to a predetermined positionin the inkjet apparatus 46, and a control device 54 which controls theentire system of the inkjet apparatus 46.

The head position controller 47, the base plate position controller 48,the main scanning driver 49, and the sub-scanning driver 51 are disposedon a base 39. In addition, a cover 34 may be disposed over theabove-described devices as necessary.

As shown in FIG. 14, the inkjet head 52 includes a plurality of headchips 50 (in the present embodiment, six), and a carriage 55 whichretains the head chips 50 such that the head chips 50 are arranged in aline. The carriage 55 is provided with holes, that is, concavities,which are slightly larger than the head chips 50, at positions at whichthe head chips 50 are to be retained. The head chips 50 are individuallydisposed in the concavities, and are fixed by screws, adhesives, orother fixing techniques. In the case in which the positions of the headchips 50 relative to the carriage 55 are precisely determined, the headchips 50 may also be fixed in the concavities by press fitting.

As shown in FIG. 14(b), each of the head chips 50 includes a nozzle line58 in which a plurality of nozzles 57 are arranged in a line. The numberof the nozzles 57 is, for example, 180, and the diameter of the nozzles57 is, for example, 28 μm. In addition, the nozzle pitch between thenozzles 57 is, for example, 141 μm. In FIG. 14(a), X denotes the mainscanning direction and Y denotes the sub-scanning direction of theinkjet head 52.

While the inkjet head 52 is moved over the mother base plate 38 a inparallel to the X direction, the subpixel material or the protectingfilm material is ejected selectively from the nozzles 57 formed in thehead chips 50. Thus, the subpixel material or the protecting filmmaterial adheres to the mother base plate 38 a at predeterminedpositions. The position at which the inkjet head 52 is moved in the mainscanning direction X can be shifted by moving the inkjet head 52 apredetermined distance, for example, an integral multiple of the lengthL0 of the nozzle lines 58, in the sub-scanning direction Y.

The nozzle lines 58 are formed in the head chips 50 in such a mannerthat the nozzle lines 58 are all arranged on a line Z when the headchips 50 are attached to the carriage 55. A distance D between adjacenthead chips 50 is determined such that the distance between two nozzles57, which individually belong to adjacent head chips 50 and which areindividually disposed at ends close to each other, is the same as thelength L0 of the nozzle lines 58 in the head 50. The nozzle lines 58 arearranged in the above-described manner merely for facilitating themovement control of the inkjet head 52 in the main scanning direction Xand in the sub-scanning direction Y. Thus, the arrangement of the nozzlelines 58, that is, the arrangement of the head chips 50 relative to thecarriage 55, may also be set in various ways other than theabove-described arrangement.

FIG. 16(a) and FIG. 16(b) show the internal structure of each of thehead chips 50. More specifically, the head chip 50 includes a nozzleplate 59 formed of stainless steel, a vibrating plate 61 which opposesthe nozzle plate 59, and a plurality of partitioning plates 62 which arefixed between the nozzle plate 59 and the vibrating plate 61. Aplurality of ink cells 63 and an ink pool 64 are formed between thenozzle plate 59 and the vibrating plate 61 by the partitioning plates62. The ink cells 63 are connected to the ink pool 64 by ink passages68.

The vibrating plate 61 is provided with an ink supplying hole 66 at asuitable position, and an ink supplying device 67 is connected to theink supplying hole 66. The ink supplying device 67 supplies the subpixelmaterial M or the protecting film material M through -the ink supplyinghole 66, so that the ink pool 64 and the ink cells 63 are filled withthe subpixel material M or the protecting film material M. With respectto the subpixel material M, one of the materials corresponding to R, G,and B is supplied from the ink supplying device 67, and different headchips 50 are prepared for different colors.

The materials for forming the R, G, and B subpixels are formed bydiffusing R, G, and B coloring materials in a solvent. In addition, theprotecting film material M is formed of a transparent heat-curable resinor a transparent photocurable resin and includes, for example, at leastone of acrylic resin, epoxy resin, imide resin, and fluorocarbon resin.The viscosity of the protecting film material M is preferably set to 4to 50 cps. When the viscosity is lower than 4 cps, the fluidity of theprotecting film material M is too high so that it is difficult to form apredetermined shape, and when the viscosity is higher than 50 cps, it isdifficult to eject a predetermined amount of material through thenozzles 57.

The nozzle plate 59 is provided with the nozzles 57 for ejecting thesubpixel material M or the protecting film material M from the ink cells63. In addition, ink pressurizing members 69 are disposed on thevibrating plate 61 at the side opposite to the side at which the inkcells 63 are formed, at positions corresponding to the ink cells 63. Asshown in FIG. 16(b), each of the ink pressurizing members 69 includes apiezoelectric element 71 and a pair of electrodes 72 a and 72 b whichsandwich the piezoelectric element 71. When a voltage is applied acrossthe electrodes 72 a and 72 b, the piezoelectric element 71 deforms toswell outward in the direction shown by the arrow C, so that thecapacity of the ink cell 63 increases. Thus, the subpixel material M orthe protecting film material M flows into the ink cell 63 from the inkpool 64 through the ink passage 68 by the amount corresponding to theincreased capacity of the ink cells 63.

Then, when the voltage applied across the electrodes 72 a and 72 b isremoved, the piezoelectric element 71 and the vibrating plate 61 returnto their initial shapes, and the capacity of the ink cells 63 is reducedto the initial value. Thus, the subpixel material M or the protectingfilm material M contained in the ink cells 63 is pressurized, and isejected toward the mother base plate 38 a (see FIG. 10(a)) via thenozzle 57 as an ink drop M6 or M7. In order to prevent the ink drop M6or M7 from being stuck in the nozzle 57 or being ejected in anundesirable direction, an ink-repellent layer 73 formed of, for example,a Ni-tetrafluoroethylene deposited layer, is formed around the nozzle57.

With reference to FIG. 13, the head position controller 47 includes ancc motor 74 which rotates the inkjet head 52 around a vertical axis, a βmotor 76 which rotates the inkjet head 52 around an axis parallel to thesub-scanning direction Y, a γ motor 77 which rotates the inkjet head 52around an axis parallel to the main scanning direction X, and a Z motor78 which moves the inkjet head 52 in the vertical direction.

In addition, with reference to FIG. 13, the base plate positioncontroller 48 shown in FIG. 12 includes a table 79 on which the motherbase plate 38 a is disposed, and a θ motor 81 which rotates the table 79in a horizontal plane, as shown by the arrow θ. In addition, as shown inFIG. 13, the main scanning driver 49 shown in FIG. 12 includes a guiderail 82 which extends in the main scanning direction X and a slider 83which contains a linear motor that is driven based on pulses. The slider83 moves in parallel in the main scanning direction X along the guiderail 82 when the linear motor contained in the slider 83 is operated.

In addition, as shown in FIG. 13, the sub-scanning driver 51 shown inFIG. 12 includes a guide rail 84 which extends in the sub-scanningdirection Y and a slider 86 which contains a linear motor that is drivenbased on pulses. The slider 86 moves in paralell in the sub-scanningdirection Y along the guide rail 84 when the linear motor contained inthe slider 86 is operated.

Each of the linear motors contained in the sliders 83 and 86 can beoperated with high precision by controlling a rotation angle of anoutput shaft based on pulse signals supplied to the motors. Accordingly,the position of the inkjet head 52 that is supported by the slider 83can be controlled in the main scanning direction X with high precision,and the position of the table 79 can be controlled in the sub-scanningdirection Y with high precision. In addition to the above-describedmethod in which the pulse motors are used, the positions of the inkjethead 52 and the table 79 may also be feedback controlled using servomotors, or may be controlled by other methods.

The base plate supplying device 53 shown in FIG. 12 includes a baseplate container 87 which contains the mother base plate 38 a and a robot88 which carries the mother base plate 38 a. The robot 88 includes abase 89 which is disposed on an installing base such as the floor,ground, etc., an vertical shaft 91 which moves vertically relative tothe base 89, a first arm 92 which rotates around the vertical shaft 91,a second arm 93 which rotates relative to the first arm 92, and achucking member 94 which is disposed on the bottom surface of the secondarm 93 at the end thereof. The chucking member 94 is able to chuck themother base plate 38 a by air suction, etc.

In FIG. 12, a capping device 106 and a cleaning device 107 are disposedat one side of the sub-scanning driver 51, and at positions inside themoving region of the inkjet head 52, which-is driven by the mainscanning driver 49. In addition, an electrobalance 108 is disposed atthe other side of the sub-scanning driver 51. The cleaning device 107 isused for cleaning the inkjet head 52. The electrobalance 108 is used formeasuring the weight of an ink drop ejected from each nozzle 57 of theinkjet head 52. In addition, the capping device 106 is used forpreventing the nozzles 57 from drying while the inkjet head 52 is in astandby state.

An inkjet head camera 111 is disposed near the inkjet head 52 in such amanner that the inkjet head camera 111 and the inkjet head 52 are ableto move together. In addition, a base plate camera 112, which issupported by a supporting device (not shown) provided on the base 39, isdisposed such that the base plate camera 112 is able to observe themother base plate 38 a.

The control device 54 shown in FIG. 12 includes a main computer 96containing a processor, a keyboard 97 which serves as an input device,and a Cathode Ray Tube (CRT) display 98. As shown in FIG. 17, theabove-described processor includes a Central Processing Unit (CPU) whichperforms calculations and an information storage medium 101, that is, amemory that stores various information.

As shown in FIG. 17, the head position controller 47 shown in FIG. 12,the base plate position controller 48, the main scanning driver 49, andthe sub-scanning driver 51 shown in FIG. 12, and an inkjet head drivingcircuit 102 for driving the piezoelectric elements 71 (see FIG. 16(b))included in the inkjet head 52 are connected to the CPU 99 via aninput/output interface 103 and a bus 104. In addition, the base platesupplying device 53, the input device 97, the display 98, theelectrobalance 108, the cleaning device 107 and the capping device 106are also connected to the CPU via the input/output interface 103 and thebus 104.

The memory 101 may be a semiconductor memory such as Random AccessMemory (RAM), Read Only Memory (ROM), etc., or an external storagedevice such as a hard disk, a CD-ROM reader, a disk type storage medium,etc. The memory 101 can include a memory area for storing a softwareprogram in which operation processes of the inkjet device 46 arewritten, a memory area for storing the displacement of the slider 83 inthe main scanning direction X and the displacement of the mother baseplate 38 a in the sub-scanning direction Y shown in FIG. 13, an areawhich serves as a work area for CPU 99, temporary files, etc., andvarious other memory areas.

In the present embodiment of the liquid crystal device manufacturingmethod, particularly of the color filter manufacturing method, theinkjet device 46 is used in both the subpixel forming process (P32) andthe protecting film forming process (P33) shown in FIG. 11. The inkjetdevice 46 used in the subpixel forming process (P32) and the inkjetdevice 46 used in the protecting film forming process (P33) may havealmost the same mechanism.

As shown in FIG. 17, the memory 101 contained in the inkjet device 46used in the subpixel forming process (P32) stores a software programwhich controls the entire process of forming the subpixels, RGB positiondata, which is data of positions for forming the R, G, and B subpixelscorresponding to one of the patterns shown in FIG. 4, and RGB volumedata, which is data of the volumes of the R, G, and B subpixel materialsto be supplied at the corresponding positions. In the RGB volume data,the volumes of the subpixel materials may be determined based on thecolors, or based on coordinates on the mother base plate 38 a.

While the inkjet head 52 is moved in the main scanning direction, theCPU 99 calculates when and from which nozzle 57 the ink, that is, thesubpixel material, should be ejected based on the RGB position data andthe RGB volume data.

Similarly to the inkjet device 46 used in the subpixel forming process(P32), the memory 101 shown in FIG. 17 contained in the inkjet device 46used in the protecting film forming process (P33) stores a softwareprogram which controls the entire process of forming the protectingfilm, RGB position data, which is data of positions for forming the R,G, and B subpixels corresponding to one of the patterns shown in FIG. 4,and RGB volume data, which is data of the volumes of the R, G, and Bsubpixel materials to be supplied at the corresponding positions.

While the inkjet head 52 is moved in the main scanning direction, theCPU 99 calculates when and from which nozzle 57 the ink, that is, theprotecting film material, should be ejected based on the RGB positiondata and the RGB volume data. The volume of the protecting film materialejected from each nozzle 57 may be determined such that the top surfaceof the protecting films 17 and the top surface of the bank 14 becomeeven, as shown in FIG. 5(a). In such a case, the CPU 99 subtracts thevolume of the subpixel 16 from the capacity of the cell formed by thebank 14, and determines the calculated difference as the volume of theprotecting film material to be ejected.

Instead of storing the RGB volume data as described above, the memory101 contained in the inkjet device 46 used in the protecting filmforming process (P33) may directly store data of volumes of theprotecting film material to be supplied in association with the colorsof the subpixels.

The CPU 99 shown in FIG. 17 is used for ejecting the subpixel materialor the protecting film material toward the mother base plate 38 a at thepredetermined positions based on the software program stored in thememory 101. The CPU 99 can include a cleaning calculator which performscalculations for a cleaning process, a capping calculator which performscalculations for a capping process, a weight measurement calculatorwhich performs calculations for a weight measuring process using theelectrobalance 108 (see FIG. 12), and a scanning and ejecting calculatorwhich performs calculations for ejecting the subpixel material or theprotecting film material at the predetermined positions by the inkjetmethod.

The scanning and ejecting calculator can be divided into a startingposition calculator which performs calculations for setting the initialposition at which the inkjet head 52 starts scanning, a main scanningcontrol calculator which performs calculations for moving the inkjethead 52 in the main scanning direction X at a predetermined speed, asub-scanning control calculator which performs calculations for movingthe mother base plate 38 a by a predetermined distance in thesub-scanning direction Y, and a nozzle ejection control calculator whichperforms calculations for controlling when and from which nozzle 57 theink, that is, the subpixel material should be ejected.

Although the above-described functions are realized by the CPU 99 basedon the software program in the present embodiment, a separate electroniccircuit having such functions may also be used if possible.

The operation of the inkjet device 46, which is constructed as describedabove, will be described below with reference to a flowchart shown inFIG. 18.

When an operator turns on the power and the inkjet device 46 isactivated, initial setting is performed at S1. More specifically, thehead unit 56, the base plate supplying device 53, the control device 54,etc., are set to an initial state.

Then, when weight measurement is required (when the result is YES atS2), the head unit 56 shown in FIG. 13 is moved to the electrobalance108 shown in FIG. 12 by the main scanning driver 49 (S3), and the volumeof ink ejected from each nozzle 57 is measured by the electrobalance 108(S4). Then, the voltage applied to the piezoelectric element 71corresponding to each nozzle 57 is adjusted in accordance with the inkejection characteristic of each nozzle 57 (S5).

Then, when cleaning is required (when the result is YES at S6), the headunit 56 is moved to the cleaning device 107 by the main scanning driver49 (S7), and the cleaning device 107 cleans the inkjet head 52 (S8).

When it is determined that both weight measurement and cleaning are notto be performed (when results at S2 and S6 are both NO), or when theweight measurement and/or the cleaning ends, the mother base plate 38 ais supplied to the table 79 by activating the base plate supplyingdevice 53 shown in FIG. 12 at S9. More specifically, the mother baseplate 38 a inside the base plate container 87 is chucked by the chuckingmember 94, is transferred to the table 79 by operating the verticalshaft 91, the first arm 92, and the second arm 93, and is pushed againstpositioning pins 80 (see FIG. 13) disposed at suitable positions on thetable 79. In order to prevent the displacement of the mother base plate38 a on the table 79, the mother base plate 38 a is preferably fixed tothe table 79 by air suction, etc.

Then, the output shaft of the θ motor 81 shown in FIG. 13 is rotated insmall angular steps while the mother base plate 38 a is observed by thesubstrate camera 112 shown in FIG. 12, so that the table 79 is rotatedin the horizontal plane in small angular steps. Accordingly, the motherbase plate 38 a is positioned (S10). Then, while the mother base plate38 a is observed by the inkjet head camera 111, the position to startscanning is calculated (S11), and the main scanning driver 49 and thesub-scanning driver 51 are operated such that the inkjet head 52 ismoved to the starting position (S12). As shown in FIG. 19, the inkjethead 52 is set such that the extending direction Z of the nozzle line 58in each head chip 50 is perpendicular to the main scanning direction X.

With reference to FIG. 18, after the inkjet head 52 reaches the startingposition at S12, the inkjet head 52 starts to move in the main scanningdirection X at S13, and the ejection of the ink starts at the same time.More specifically, the main scanning driver 49 shown in FIG. 13 drivesthe inkjet head 52 in the main scanning direction X shown in FIG. 19 ata constant speed. While the inkjet head 52 is moved, the nozzles 57eject the subpixel material or the protecting film material when theyreach the sections which are to receive the subpixel material or theprotecting film material. FIG. 19(b) schematically shows the manner inwhich the subpixel material M or the protecting film material M issupplied to the sections formed by the bank 14 in the form of ink drops.

In FIG. 19(a), when the inkjet head 52 finishes a single scan in themain scanning direction over the mother base plate 38 a (when the resultis YES at S14), the inkjet head 52 returns to the initial position(S15). Then, the sub-scanning driver 51 drives the inkjet head 52 by apredetermined distance in the sub-scanning direction Y, for example, anintegral multiple of the length of a single nozzle line 58 (S16). Then,the main scanning and the ejection of the ink are repeated, so that thesubpixels 16 or the protecting films 17 are formed in the cells whichare still empty (S13).

After the inkjet head 52 finishes a single main scan, the inkjet head 52may be immediately moved in the sub-scanning direction Y without movingthe inkjet head 52 back to the initial position, and then moved rearwardin the main scanning direction X while the subpixel material or theprotecting film material is ejected. In such a case, the main scanningfor ejecting ink is performed not only when the inkjet head 52 is movedforward in the main scanning direction X but also when the inkjet headis moved rearward in the main scanning direction X.

When the inkjet head 52 finishes forming the subpixels 16 or theprotecting films 17 over the entire area of the mother base plate 38 a(when the result is YES at S17), the mother base plate 38 a istransferred out by the base plate supplying device 53 or by othertransferring devices at S18. Then, unless a command to end the operationis issued by the operator (unless the result at S19 is YES), the processreturns to S2 and the operation of ejecting the subpixel material or theprotecting film material toward another mother base plate 38 a starts.

When the command to end the operation is issued by the operator (whenthe result at S19 is YES), the CPU 99 controls the inkjet head 52 suchthat the inkjet head 52 is transferred to the capping device 106 shownin FIG. 12. Then, the inkjet head 52 is subjected to the capping processby the capping device 106 (S20). Accordingly, the operation ofpatterning the subpixels 16 or the protecting films 17 in the colorfilter 11 is completed. Then, the above-described process of forming thefirst electrodes 12 a (P3 in FIG. 9) is performed.

As described above, according to the liquid crystal device manufacturingmethod of the present embodiment, each of the subpixels 16 shown in FIG.11 is formed by the inkjet method. Thus, the relationships between theopenings 18 formed in the light reflecting film 9 and the subpixels 16can be individually adjusted, so that the colors displayed by thesubpixels 16 can be individually and precisely adjusted. Accordingly,uniform color display over the display area can be realized.

FIG. 15 shows a modification of the head chips 50 shown in FIG. 14(b).With reference to FIG. 14(b), each of the head chips 50 can be providedwith a single nozzle line 58 in the main scan direction X. However, thehead chip 50 may also be provided with a plurality of nozzle lines 58which are arranged in the main scanning direction X (in FIG. 15, twonozzle lines 58 are formed). By using this head chip 50, since the inkcan be ejected from two lines of nozzles 57 arranged in the mainscanning direction X, ejection of the subpixel material or theprotecting film material can be controlled in various ways while thecarriage 55 (see FIG. 14(a)) is moved in the main scanning direction X.

FIG. 20 shows a main process, especially a color filter forming process,of a liquid crystal device manufacturing method according to anotherembodiment. This process is performed in place of the process shown inFIG. 19 which is described in the above-described embodiment. The colorfilter manufactured by the manufacturing method of the presentembodiment is the same as the color filter denoted by reference numeral11 in FIG. 5. In addition, a plurality of color filters 11 can be formedon the mother base plate 38 a shown in FIG. 10(a) at the same time.

In addition, the pattern of the subpixels 16 formed in the color filter11 may be one of the patterns shown in FIG. 4 (the striped pattern,etc.), and the color filter 11 may be formed by the processes shown inFIG. 11 (P31 to P33). In addition, the inkjet device used in thesubpixel forming process (P32) and the inkjet device used in theprotecting film forming process (P33) may be constructed as shown inFIG. 12.

As is apparent from FIGS. 19 and 20, the present embodiment is differentfrom the above-described embodiment in that, when the inkjet head 52 isdisposed at the initial position, that is, at the main scan startingposition, above the mother base plate 38 a, the entire body of thecarriage 55 is inclined relative to the sub-scanning direction Y by anangle θ. Thus, the extending direction Z of six nozzle lines 58 is alsoinclined relative to the sub-scanning direction Y by the angle θ.

According to the present embodiment, the head chips 50 are moved in themain scanning direction X while they are inclined relative to thesub-scanning direction Y by the angle θ. Thus, the pitch between thenozzles 57 formed in each head chip 50 can be made the same as the pitchbetween the sections in which the subpixels 16 and the protecting films17 are formed, that is, the pitch between the elements. When the pitchbetween the nozzles 57 and the pitch between the elements are made thesame as described above, it is not necessary to adjust the position ofthe nozzle lines 58 in the sub-scanning direction Y.

FIG. 21 shows a main process, especially an another color filter formingprocess, of a liquid crystal device manufacturing method according toanother embodiment. This process is also performed in place of theprocess shown in FIG. 19 which is described in the above-describedembodiment. The color filter substrate manufactured by the manufacturingmethod of the present embodiment is the same as the color filter forliquid crystal denoted by reference numeral 11 in FIG. 5. In addition, aplurality of color filters 11 can be formed on the mother base plate 38a shown in FIG. 10(a) at the same time.

In addition, the pattern of the subpixels 16 formed in the color filter11 may be one of the patterns shown in FIG. 4 (the striped pattern,etc.), and the color filter 11 may be formed by the processes shown inFIG. 11 (P31 to P33). In addition, the inkjet device used in thesubpixel forming process (P32) and the inkjet device used in theprotecting film forming process (P33) may be constructed as shown inFIG. 12.

As is apparent from FIGS. 19 and 21, the present embodiment is differentfrom the above-described embodiment in that, when the inkjet head 52 isdisposed at the initial position, that is, at the main scan startingposition, above the mother base plate 38 a, six head chips 50 areinclined relative to the sub-scanning direction Y by an angle θ althoughthe entire body of the carriage 55 is not inclined. Thus, the extendingdirection Z of each nozzle line 58 is also inclined relative to thesub-scanning direction Y by the angle θ.

According to the present embodiment, the head chips 50 are moved in themain scanning direction X while they are inclined relative to thesub-scanning direction Y by the angle θ. Thus, the pitch between thenozzles 57 in each nozzle line 58 can be made the same as the pitchbetween the sections in which the subpixels 16 and the protecting films17 are formed, that is, the pitch between the elements. When the pitchbetween the nozzles 57 and the pitch between the elements are made thesame as described above, it is not necessary to adjust the position ofthe nozzle lines 58 in the sub-scanning direction Y.

In addition, according to the present embodiment, the entire body of thecarriage 55 is not inclined as shown in FIG. 20, rather, only the headchips 50 are inclined. Thus, the distance between the nozzle 57 that isclosest to the mother base plate 38 a to be ejected and the nozzle 57that is farthest from the mother base plate 38 a can be significantlyreduced relative to the case shown in FIG. 20. Thus, the time intervalduring which the inkjet head 52 is moved in the main scanning directionX can be reduced, and the manufacturing time of the color filter can bereduced.

In the embodiment shown in FIGS. 5, 6, 7, and 8, the subpixels 16 areformed in the section defined by the bank 14 in a convex shape such thatthe central parts thereof swell upward, in other words, shaped like adome. This shape can be formed when the subpixel material supplied bythe inkjet method is dried slowly and at low temperature, for example,at 40° C. for about 10 minutes.

As shown in FIG. 22, instead of forming the subpixels 16 in theabove-described shape, it should be understood that the subpixels 16 mayalso be formed in a concave shape such that the central parts thereofare hollow. This shape can be formed when the subpixel material suppliedby the inkjet method is dried quickly and at high temperature, forexample, at 100° C. for about 1 minutes. In the drying process at such ahigh temperature, the tolerance range of the temperature is largecompared with a drying process at a low temperature, so that thetemperature can be easily controlled, and the time necessary for thedrying process can be reduced.

As shown in FIG. 22, in the case in which the subpixels 16 are formed inthe concave shape, the openings 18 of the light reflecting film 9 areformed at the peripheral regions of the sections formed by the bank 14.That is, the openings 18 are formed in an annular shape at regionscorresponding to the thick parts of the subpixels 16. Accordingly, thelength of the optical path in the subpixels 16 in the reflective displaymode and that in the transmissive display mode can be made close orapproximately the same, so that the color display can be made uniformbetween the reflective display mode and the transmissive display mode.

Also in the present embodiment, the corners of the openings 18 may beformed as beveled corners Ml shown in FIG. 6(b) or as rounded corners M2shown in FIG. 7(b). In addition, the openings 18 may also be formed inthe light reflecting film 9 along one of the interference fringes F,which correspond to the thickness distribution of the subpixels 16, asshown in FIG. 8(b).

In FIG. 22, the components similar to those shown in FIG. 5 are denotedby the same reference numerals and the explanations thereof are omitted.

FIG. 23 shows a modification of the openings 18 in the light reflectingfilm 9. Openings 18 shown in FIG. 23 differ from those shown in FIG. 22in that the openings 18 are formed along the longitudinal direction ofthe rectangular sections formed by the bank 14 (that is, the verticaldirection in FIG. 23(b)), in the peripheral region thereof. Except forthis, the present modification is the same as the embodiment shown inFIG. 22.

FIG. 24 shows another modification of the openings 18 in the lightreflecting film 9. Openings 18 shown in FIG. 24 differ from those shownin FIG. 22 in that the openings 18 are formed along the lateraldirection of the rectangular sections formed by the bank 14 (that is,the horizontal direction in FIG. 24(b)), in the peripheral regionthereof. Except for the differing openings, the present modification isthe same as the embodiment shown in FIG. 22.

FIG. 25 shows another modification of the openings 18 in the lightreflecting film 9. Openings 18 shown in FIG. 25 differ from those shownin FIG. 22 in that the openings 18 are formed at four corners of therectangular sections formed by the bank 14 in a columnar shape, that is,a circular shape in cross section. Except for the differing openings,the present modification is the same as the embodiment shown in FIG. 22.

FIG. 26 shows a mobile phone according to an embodiment of an electronicdevice of the present invention. In FIG. 26, a mobile phone 120 includesa display 121 which is constructed of a liquid crystal device, anantenna 122, a speaker 123, a key switch group 124, and a microphone125. The liquid crystal device 121, which functions as a display, isconstructed of, for example, the liquid crystal device 1 shown in FIG.1.

FIG. 27 shows a watch according to another embodiment of an electronicdevice of the present invention. In FIG. 27, a watch 130 includes aliquid crystal device 131 which serves as a display. The liquid crystaldevice 131 is constructed of, for example, the liquid crystal device 1shown in FIG. 1.

FIG. 28 shows a portable information processor according to anotherembodiment of an electronic device of the present invention. In FIG. 28,a portable information processor 140 functions as, for example, a wordprocessor, a personal computer, etc., and includes a main body 141, aninput device 142 such as keyboard, etc. disposed on the exterior of themain body 141, and a liquid crystal device 143 which functions as adisplay. A processor contained inside the main body performscalculations based on the information input via the keyboard 142, andthe results are displayed on the liquid crystal device 143.

Although the preferred embodiments of the present invention have beendescribed, it should be understood that the present invention is notlimited to the above-described embodiments, and various modificationscan be made within the scope of the present invention which is disclosedin the claims.

For example, although the R, G, and B subpixels are used in theforegoing descriptions, C(cyan), M(magenta), and Y(yellow) subpixels mayalso be used. In such a case, materials for forming the subpixels of C,M, and Y may be used instead of the materials for forming the R, G, andB subpixels.

In addition, although six head chips 50 are disposed in a single inkjethead 52 in the above-described embodiments, as shown in FIG. 14, thenumber of head chips 50 may be increased or reduced.

In addition, in the embodiment shown in FIGS. 10(a) and 10(b), aplurality of lines of first substrates 3 a are formed in the firstmother base plate 38 a, and a plurality of lines of second substrates 3b are formed in the second mother base plate 38 b. However, the presentinvention may also be applied in the case in which a single line offirst substrates 3 a is formed in the first mother base plate 38 a and asingle line of second substrates 3 b is formed in the second mother baseplate 38 b. In addition, the present invention may also be applied inthe case in which a single first substrate 3 a having the same orsmaller size relative to the first mother base plate 38 a is formed onthe first mother base plate 38 a, and a single second substrate 3 bhaving the same or smaller size relative to the second mother base plate38 b is formed on the second mother base plate 38 b.

In addition, in the inkjet device 46 shown in FIGS. 12 and 13, theinkjet head 52 is moved in the X direction for main scanning over thebase plate 38 a. In addition, the mother base plate 38 a is moved in theY direction by the sub-scanning driver 51 for the sub-scanning of theinkjet head 52 over the mother base plate 38 a. However, the mother baseplate 38 a may be moved in the Y direction for the main scanning and theinkjet head 52 may be moved in the X direction for the sub-scanning.

In addition, although the inkjet head in which ink is ejected bydeforming piezoelectric elements are used in the above-describedembodiments, an inkjet head having other constructions may also be used.

In addition, the protecting films 17 may be formed using methods otherthan the inkjet method, for example, spin coating, roll coating,printing, etc.

As described above, according to the present invention, the openings areformed in the light reflecting film at regions corresponding to thethickest parts of the subpixels. In addition, the openings are formed inthe light reflecting film at regions corresponding to the centralregions of the subpixels. In addition, the openings are formed in thelight reflecting film in such a manner that the openings extend in thelongitudinal direction of the subpixels. Accordingly, color displaywhich is uniform over the display area, and which is uniform between thereflective display mode and the transmissive display mode can beobtained.

While this invention has been described in conjunction with the specificembodiments thereof, it is evident that many alternatives, modificationsand variations will be apparent to those skilled in the art.Accordingly, preferred embodiments of the invention as set forth hereinare intended to be illustrative not limiting. There are changes that maybe made without departing from the spirit and scope of the invention.

1. A liquid crystal device, comprising: a pair of substrates whichsandwich liquid crystal therebetween; a light reflecting film formed onat least one of the substrates; and a color filter formed on the lightreflecting film, wherein the color filter includes a partitioning memberthat divides a surface of the substrate into a plurality of sections andsubpixels that are individually formed in the sections, and whereinopenings are formed in the light reflecting film at regionscorresponding to thickest parts of the subpixels.
 2. A liquid crystaldevice according to claim 1, wherein the openings have a shape such thatcorners thereof are cut off.
 3. A liquid crystal device according toclaim 1, wherein the planner shape of the opening is at least one of arectangular shape, an oval shape, and an elliptical shape.
 4. A liquidcrystal device according to claim 1, wherein an area of a single openingis 5% to 30% of an area of a single section.
 5. A liquid crystal deviceaccording to claim 1, wherein the subpixels are formed in a convex shapesuch that central portions thereof swell upward.
 6. An electronicdevice, comprising: a liquid crystal device according to claim 1; and ahousing which contains the liquid crystal device.
 7. A liquid crystaldevice, comprising: a pair of substrates which sandwich liquid crystaltherebetween; a light reflecting film formed on at least one of thesubstrates; and a color filter formed on the light reflecting film,wherein the color filter includes a partitioning member that divides thesurface of the substrate into a plurality of sections and subpixels thatare individually formed in the sections, and wherein openings are formedin the light reflecting film at regions corresponding to central partsof the sections.
 8. A liquid crystal device, comprising: a pair ofsubstrates which sandwich liquid crystal therebetween; a lightreflecting film formed on at least one of the substrates; and a colorfilter formed on the light reflecting film, wherein the color filterincludes a partitioning member that divides a surface of the substrateinto a plurality of rectangular sections and subpixels that areindividually formed in the rectangular sections, and wherein openingsare formed in the light reflecting film in such a manner that theopenings extend in a longitudinal direction of the rectangular sections.9. A liquid crystal device, comprising: a pair of substrates whichsandwich liquid crystal therebetween; a light reflecting film formed onat least one of the substrates; and a color filter formed on the lightreflecting film, wherein the color filter includes a partitioning memberthat divides a surface of the substrate into a plurality of sections andsubpixels that are individually formed in the sections, and whereinopenings are formed in the light reflecting film in such a manner thatthe openings have a shape corresponding to a thickness distribution ofthe subpixels.
 10. A liquid crystal device, comprising: a pair ofsubstrates which sandwich liquid crystal therebetween; a lightreflecting film formed on at least one of the substrates; and a colorfilter formed on the light reflecting film, wherein the color filterincludes a partitioning member that divides the surface of the substrateinto a plurality of sections, and subpixels that are individually formedin the sections, wherein the subpixels are formed in a concave shapesuch that central portions thereof are hollow, and wherein openings areformed in the light reflecting film at regions corresponding to thickestparts of the subpixels.
 11. A liquid crystal device, comprising: a pairof substrates which sandwich liquid crystal therebetween; a lightreflecting film formed on at least one of the substrates; and a colorfilter formed on the light reflecting film, wherein the color filterincludes a partitioning member that divides a surface of the substrateinto a plurality of sections and subpixels that are individually formedin the sections, wherein the subpixels are formed in a concave shapesuch that central portions thereof are hollow, and wherein openings areformed in the light reflecting film at regions corresponding toperipheral parts of the sections in such a manner that peripheralportions of the sections are partly or entirely covered by the openings.12. A liquid crystal device, comprising: a pair of substrates whichsandwich liquid crystal therebetween; a light reflecting film formed onat least one of the substrates; and a color filter formed on the lightreflecting film, wherein the color filter includes a partitioning memberthat divides the surface of the substrate into a plurality ofrectangular sections and subpixels that are individually formed in therectangular sections, wherein the subpixels are formed in a concaveshape such that central portions thereof are hollow, and whereinopenings are formed in the light reflecting film in such a manner thatthe openings extend in a longitudinal direction or a lateral directionof the rectangular sections at regions corresponding to peripheral partsof the rectangular sections.
 13. A liquid crystal device, comprising: apair of substrates which sandwich liquid crystal therebetween; a lightreflecting film formed on at least one of the substrates; and a colorfilter formed on the light reflecting film, wherein the color filterincludes a partitioning member that divides a surface of the substrateinto a plurality of sections and subpixels that are individually formedin the sections, wherein the subpixels are formed in a concave shapesuch that central portions thereof are hollow, and wherein openings areformed in the light reflecting film in such a manner that the openingshave a shape corresponding to a thickness distribution of the subpixels.